Maybe a little harsh for a non patron, I'd be furious otherwise.Well I think you are being a little harsh.
Patreon is useful for online content creators, where patrons basically pay for the creation of new content on a daily/weekly/monthly basis. When it's used to create a video game, which has no clear timeline, no set milestones, not even a deadline, it's open to abuse and exploitation.I think this Developer isn't milking Patreon, but went for a complex game and that complexity is slowing the game down.